Fast Refresh comes in two cooperating pieces: the dev server that watches app/ and pushes changed files to every connected client, and this device-side module reloader that swaps the new code in and refreshes every mounted screen. Debug builds launched with pn run while pn start is running are wired up automatically.

::: pythonnative.hot_reload options: show_root_heading: false show_root_toc_entry: false members_order: source filters: ["!^_"]

• See the workflow in the Fast Refresh guide.
• The other half: Dev server and dev client.